The phosphate rock industry is an outstanding example of industrial and ecological achievement through the use of modern mining techniques, improved ore dressing methods and novel ecologically oriented practices.
New developments in each of these areas has resulted in increased output and recovery of the vital mineral product from the mineral deposit, marked extension of the life of the phosphate fields and conservation of water resources through recycle. The improved practices have also resulted in elimination or minimization of land and water pollution hazards normally associated with disposal of waste slimes produced in ore processing plants and in the reclamation of otherwise useless land by formulating waste slimes and tails into a reconstituted fertile soil having acceptable bearing strength. Processes for achieving these desirable results are described in U.S. Pat. to C. C. Cook and E. M. Haynsworth, No. 3,718,003; No. 3,763,041 and No. 3,761,239, issued Feb. 27, Oct. 2 and Sep. 25, 1973, respectively, and M. L. Lassiter, No. 3,940,071, issued Feb. 24, 1976.
The benefits derived from these improved practices are dramatic and accrue to both the industry and the public alike. However, these benefits are not derived without (a) utilization of additional equipment, (b) an increase in the labor force required to install, operate and maintain said equipment, and (c) a marked increase in power consumption.
Now, in light of diminishing fuel reserves, skyrocketing costs for electrical energy and significantly increasing equipment costs, especially for large diameter steel pipe required by the modern practices for moving high pressure water, tailing, slimes and matrix between the mine, the phosphate recovery plant and the waste disposal area, it becomes exceedingly apparent that still further technological advances are required to achieve the desirable results afforded by the above-mentioned practices; but, to achieve such results with greatly reduced power consumption and minimized equipment and labor costs.
The magnitude of the problems confronting the industry, as regards increasing energy costs and usage of large diameter steel pipe is evidenced by the fact that energy costs for a typical modern phosphate mining operation have nearly quadrupled in the past five years; and further, by the fact that such an operation will normally require replacement of approximately 20,000 to 30,000 feet of large diameter, i.e. 16 to 20 inches, steel pipe annually.
It is, therefore, an object of the present invention to provide an improved method and apparatus for processing hydraulically mined ore slurries, particularly phosphatic ore slurries, whereby power consumption per ton of ore processed is markedly reduced.
It is also an object of this invention to eliminate or minimize pipe errosion and maintenance problems encountered in the conventional processing of hydraulically mined ore slurries by replacing the slurry pump transport of matrix and plant tailings with an endless belt conveyor system.
It is a further object of this invention to provide a method for processing matrix slurries, wherein said matrix slurries are dewatered and deslimed at or near the active mining operation such that pumping of the matrix slurry over extended distances is eliminated.
It is a still further object of this invention to provide a method for transporting wet, deslimed, phosphate matrix from an active mining operation to an ore dressing plant via a continuous belt, while simultaneously transporting tailings from the ore dressing plant for use at a land reclamation excavation, near or adjacent the active mining operation, using the same said continuous belt.